The present invention relates to a method of removing heavy tar produced in a coke oven during its cooling from a coke-oven gas. The invention also relates to an apparatus for carrying out the above method.
It has been known that during the cooling of the coke-oven gas a tar-containing condensate is separated from a raw gas. This condensate is first fed into a suitable collecting container (tar separator) in which the condensate is separated into a water phase, a tar phase and a heavy tar phase. The tar phase is normally further dewatered in a pressure separator whereby a portion of a so-called heavy tar can be further separated from the tar. A particularly viscous and slurry-like tar fraction is identified as a heavy tar which includes a specifically high content of solid materials, particularly coal and coal dust.
The exemplified composition of the typical heavy tar removed from the coke-oven gas is as follows:
Tar: about 40-70 weight % PA0 Solid substances (coal, coke, graphite): about 30-50 weight % PA0 Water: about 10 weight %
The quantity of the heavy tar produced in the coke-oven, the batteries of which have been charged with wet coal, amounts to about 3-9 kg of the heavy tar per 1000 M.sup.3 n of the coke-oven gas. If the coke oven batteries are loaded with a preheated coal the quantity of the accumulated heavy tar can be increased up to 50-100% as compared to the above disclosed quantity. Because of the high content of the solid materials in the heavy tar a processing of the heavy tar in a consecutive tar destillation is not possible. Since no other possibilities of the processing of the heavy tar have been suggested in the industry, the heavy tar must have been removed from the coke-oven.